All posts by gjohn125

A six month Ban on Cod fishing In Gulf Of Maine As Stocks Decline

November  2014, The National Oceanic and Atmospheric Administration put a six month ban on commercial and recreational fishing of cod from Provincetown, Massachusetts, up to the Canadian border, due to declining cod populations. The ban has angered many fishermen who feel like the government hasn’t done enough to manage cod stocks and that NOAA’s assessment could be wrong. Since 1982, when monitoring of cod stocks began, there was a 90% decline of cod in the Gulf of Maine. Within the past five years stocks have declined by 77%. Despite decades of regulations cod stocks are at 3% to 4% of what a well-managed population should be at.  In efforts to take pressure off cod stocks, organizations such as The Center for Biological Diversity, Turtle Island Restoration Network, Sandy Hook Sea Life Foundation and Greenpeace filed a petition under the Administrative Procedure Act, which insists Fisheries Service to follow the Magnuson-Stevens Fishery Conservation and Management Act requirement to rebuild overfished species. Apart of this petition it stated that quota limits for other targeted fish like haddock should be raised, to reduce mortality of cod, allowing them to multiply and expand their habitat.

To soften the blow of the ban and previous cod quota cuts, Congress allocated $32.8 million to the New England groundfish fishery. One-third of the money went to fishermen, one-third to individual states to use at their own discretion, and one-third to federal and state representatives to create programs to pay fishermen to exit the fishery.


Audio: NPR report



A Brief History of Early Alaskan Fisheries

In the pre-Russian period, Alaska’s fisheries were managed by individual tribes (Eskimo, Indian, or Aleut) or villages based on customs, religion, or tribal law. Some individuals were given rights to harvest from a specific area or stream. During this time about over 12 million salmon were harvested annually. When the Russians landed in 1741, this led to a period of exploitation by fur traders. Fish were mostly harvested for subsistence use, but there was some commercialization. In 1799 the Russian government commissioned the Russian American company. Here the only Fishery management that occurred was directed towards commercial which led to more exploitation of resources at the expense of others in the region.

In 1867 The United States purchased Alaska; the U.S. commission of fish and fisheries conducted many studies on the fisheries resources of Alaska, however they did not play an active role in managing these fisheries. Compared to today’s fisheries, early fisheries were not as widespread or complex, and thus little attention was showed in the management of individual stocks. In 1878 the first cannery was established in southeast Alaska, and thus the fishery expanded.  By the 1930’s research and investigation of Alaskan fisheries raised an alarm that better management of individual stocks and areas needed to exist, in order to prevent mass decline of stocks. This led to federal actions to protect the stocks, which still occurs today.


mfr50433 early Alaska



The Effects of Ocean Acidification on Alaska’s Crab fishery

With rising Carbon dioxide levels many Scientist are worried about the unpredictable future of Alaska’s King crab fishery.The loss of King  crab could  have major impact  on Human consumption/ and how much King crab is harvested in commercial fishing  which effects our  economy ( money   and jobs).

One major concern about high CO2 levels is when Carbonic acid releases a H+ ion it joins with a carbonate ion leaving  calcium alone with no way to form Calcium carbonate.   Corrosive waters have a much lower concentration of calcium carbonate making it hard for organisms  such as crabs that need  the calcium carbonate  for exoskeleton growth.

A study done by Robert Froy and colleagues experimented with Red king crab that was harvested in 2009 from Bristol Bay, Alaska.   In this study Brooding females were placed in two environments (controlled:   pH 8.0; acidified environment: pH 7.7) to get a better understanding of the effect of ocean acidification on embryo development and larvae release.   They placed larvae in both the control and test environment to determine whether ocean acidification would have effects on larvae survival and they also looked at effects over different life stages.   In this study the CO2 was used to acidify waters in several tanks: the figure below shows the setup system that was used to supply acidified and control seawater to experimental tank. Crabs in this study were selected randomly and placed in either the control tank or acidic tank.

red crab tank

The study showed that a slight change to the pH in water can have effects on embryogenesis, larvae development / survival, and molting of the adult females.   For future studies the researcher wants to look at pH and temperature how this could potentially lower Red king crab tolerance.

So what does this mean for future crab populations?

In the 1970’s and 1980’s crab population crashed near Kodiak Island. For years a shellfish hatchery has been experimenting with learning how to raise baby king crab from scratch, in order to release these crabs in areas where their species have been exhausted.  Scientists believe this might be a way to remedy the future loss of king crab if the threats of ocean acidification persist.

Potential impact on Alaska's red king crab industry


Long WC, Swiney KM, Harris C, Page HN, Foy RJ (2013) Effects of Ocean Acidification on Juvenile Red King Crab (Paralithodes camtschaticus) and Tanner Crab (Chionoecetes bairdi) Growth, Condition, Calcification, and Survival. PLoS ONE 8(4): e60959. doi:10.1371/journal.pone.0060959

Article Citation: W. Christopher Long, Katherine M. Swiney, and Robert J. Foy . Effects of ocean acidification on the embryos and larvae of red king crab, Paralithodes camtschaticus. Marine Pollution Bulletin, Volume 69, Issues 1—2, 15 April 2013, Pages 38—47.

Video link: Lucrative crab industry in danger


Alaska Pollock one of the largest sustainable fisheries in the world

Alaska Pollock is one of the largest sustainable fisheries in the world and is divided  in to two stocks, the Bering Sea/Aleutian Island stock and the Gulf of Alaska stock.  The Eastern Bering Sea fishery is the largest by volume in the United States with annual total allowable catches of 1.3 million tons. From 1977-2011 the average catch from the eastern Bering Sea was 1.17 million tons. From 2012-2014 the catch of eastern Bering Sea Pollock increased to an average of 1.26 million tons. The Gulf of Alaska stock is much smaller than  the  eastern Bering Sea stock. Over the last two decades there have been  relatively low abundance of Pollock in the Gulf of Alaska, but the population appears to be stable .


Harvesting: Fishing methods for the eastern Bering Sea consist of catcher/processor vessels that process their catch at sea and trawl catchers that transport their catch onshore for processing .  90% of the fish caught from the Gulf of Alaska are done by pelagic trawl.  Products that are made from Pollock were valued at $1 billion; products include surimi, fish meal, fillets, deep skin fillets, and roe.


NOAA: Pollock biomass up 60% in Bering Sea:

Walleye Pollock species page:

Walleye Pollock facts sheet:

Marine Stewardship Council:

Management Measures for Longline Tuna Fisheries in American Samoa and Other US Pacific Islands


images (1)

On March 13, 2015 the scientific and Statistical Committee (SSC) of the Western Pacific Regional Fishery Management Council recommended management measures for longline fisheries in American Samoa and other US Pacific Islands, including Hawaii. The first recommended measure looks to establish an exemption area within American Samoa Large Vessel Prohibited Area (LVPA). In these area about 16,817 square nm would be opened to federally permitted American Samoa longline vessels of 50 feet or greater, while limiting them from 11.3% of the US exclusive economic zone around American Samoa. This measure would be design to help with economic hardships for the remaining 19 large longline vessels in the American Samoa fleet that mainly go after albacore tuna which makes up 80% of their catch, followed by yellowfin and bigeye tuna and mahimahi ( dolphinfish).  Having these exemption areas could potentially provide access to more fishing areas that are closer to shore which would lower the cost of vessels going out.  The fish that are caught by the fleets go to local canneries which provide countless jobs for people in the territory.

The second measure recommended would look to set an annual catch limit of 5,425 metric tons for Southern Pacific albacore in the US EEZ around American Samoa.  The third measure recommended would also look to establish an annual catch limit of 2000 metric tons for longline caught bigeye tuna for American Samoa, Guam and the Commonwealth of  the Northern Mariana Islands (CNMI). The Council will consider these recommendation at its 162nd  council meeting that will be held on March 16th – 18th.

download (1)download


information for the Council meeting

Western Pacific Regional Fishery Management Council  logo:

Tuna Picture:


Hello! My name is Channa argus, but my friends call me the northern Snakehead!

Scientific Name: Channa Argus

Common Name: Northern Snakehead

Origin: Native to parts of Africa and Asia. Was introduced to the United States in 2002 by fisherman and the fish market.

Impacts: Listed as injurious wildlife under federal Lacey Act, which makes it illegal to import, export , or transport between states without a permit. The snakehead fish is an invasive species that competes with native species of Maryland, Virginia, New York, Pennsylvania, and Arkansas. if fish is caught in Maryland or Virginia, people are instructed to kill it.



Trophic Status:  The snakehead is a predator that feeds on other fish species, frogs, and crustacean.

Appearance: It had an elongated body with a wicked snake-like skin pattern ( tan, dark brown and or black).  It has a long dorsal fin, a large mouth with sharp teeth, and can grow 33 inches long.  Young snakeheads are golden brown or pale gray.


Habitats:  The Northern Snakehead enjoys spending time living in ponds, lakes, streams, rivers and other freshwater areas. it likes to spend its  vacation time out of the water .  This normally last up to four days if It is kept hydrated/moist. It is  able to get away with being out of water because It can breathe air from the atmosphere using an air bladder that is similar to a pair of lungs. This poses a problem because these fish can move to other bodies of water and competing with native species.


Reproductive Life cycle:  Females can  lay more than 15,000 eggs 1 to 5 times per year. Fish spawn in June-July. larvae nest is  gaurded by both male and female snakeheads.

Sexual Maturity: 2 years of age.






Movies about Snakehead fish: ” Night of the Snakehead ” ( released in 2004), ” Snakehead Terror” ( released in 2004), and “Swarm of the Snakehead” ( released in 2006)

Sources:  ( A Must Read)

How Pacific bluefin tuna hearts maintain function as these fish dive from warm waters into cooler waters in search of prey

Researchers are trying to figure out how does Pacific bluefin tuna hearts maintain function as these fish dive from relatively warm waters of the sea surface into cooler waters in search of prey. Pacific bluefin tuna are unique because their bodies are almost endothermic, similar to that of humans. These fish are capable of elevating their core body temperatures up to 20 °C above that of the surrounding water.  As these fish dive their heart temperature can drop to 15 °C within minutes, this is due to the fact that the heart is receiving blood directly from the gills which reflects water temperature. Professor Barbara Block at Stanford stated that, “Tunas are at a unique place in bony fish evolution. Their bodies are almost like ours — endothermic, but their heart is running as all fish at ambient temperatures. How the heart keeps pumping as the fish moves into the colder water is the key to their expanded global range.”

This is a Bluefin Tuna at the Hopkins Marine Station, Monterey Bay Aquarium in California. Credit: © Monterey Bay Aquarium/Randy Wilder

In order to solve this puzzle, Researchers from Manchester’s Medical and Human Sciences Faculty worked at the Tuna Research and Conservation Center at Stanford University. Here researchers used electronic tags to monitor wild bluefin tuna, as a result they were able to get important data on the fish range of depth , internal body temperature and the ambient water temperature (3.4 to 27 °C, this includes mean sea surface temperature of 17.36 °C ± 0.05). The data revealed that the tuna have a broad range in their thermal tolerance as they migrate from the western to eastern Pacific oceans.

The researchers noticed that the tagged fish showed interesting behaviors during their dives. For example when in search of prey these fish would  display some sort of “ bounce’ dive swimming down into colder depths (500 or greater) and then quickly resurfacing into warmer surface waters. Here researchers were able to figure out that by activating adrenalin during these bounce dives was a way for  the fish to adjust electrical activity of their heart cells to maintain constant calcium cycling in order to keep the heart going. For future studies the researchers from Manchester’s Medical and Human Sciences Faculty hope to monitor how bluefin tuna react to warmer temperatures, which is useful since the temperature of our planet is increasing.





Figure  1.  

Archival tag record of a juvenile Pacific bluefin tuna off the coast of California, 19—20 June 2012. Archival tag time series shows depth from pressure (blue), internal body temperature from position of archival tag in the peritoneal cavity (red) and ambient water temperature from an external sensor (green). Juvenile bluefin tuna demonstrate rapid bouts of diving associated with foraging behaviours that occur prior to a visceral heat increment of feeding event (peritoneal warming). This bounce diving, where time at depth is short, and interspersed regularly with time at the surface, may be due to cold-induced cardiac bradycardia and subsequent oxygen delivery limitations.



H. A. Shiels, G. L. J. Galli, B. A. Block. Cardiac function in an endothermic fish: cellular mechanisms for overcoming acute thermal challenges during diving. Proceedings of the Royal Society B: Biological Sciences, 2014; 282 (1800): 20141989 DOI: 10.1098/rspb.2014.1989

Manchester University. “How tuna stay warm with cold hearts.” ScienceDaily. ScienceDaily, 5 February 2015. <>.